Centris / digger Bee
Male Centris rhodopus perched on a Bebbia juncea seed head. © Rollin Coville
Female Centris rhodopus visiting smoke tree flowers (Psorothamnus spinosus). © Rollin Coville
Female Centris rhodopus visiting smoke tree flowers (Psorothamnus spinosus). © Rollin Coville
Male Centris rhodopus perched on a Bebbia juncea seed head. © Rollin Coville
Family: Apidae
Genus: Centris
Common Name: Digger Bee
APPEARANCE
Physical Appearance
Centris species tend to be very robust, hairy bees. Both the head and thorax of most species are covered in dense pale hairs. The abdomen is usually black, red, or yellow, sometimes with a thin covering of pale hair. Both females and males have conspicuously hairy hind legs, especially the females which tend to have very prominent scopae.
The eyes of many species are very distinctive in both size and color, which can be red, green or yellow.
The female carries pollen in a brush of specialized hairs, called a scopa, on each hind leg. The females of many Centris species, particularly those which transport plant oils, have extremely bushy scopae covering their hind legs.
Characteristics
Centris species are very fast fliers and quite adept at hovering; they often make a loud humming noise during flight.
They are equipped with long tongues which allow them to extract nectar or oils from deep tubular flowers. The females of some species are distinguished by collecting plant oils instead of nectar to provision the nests for their offspring. The female also uses the oils to waterproof the brood cells.
Centris species will collect pollen from a range of plants, with Psorothamnus spinosus (smoketree), Larrea (creosote bush) and Prosopis (mesquite), being particularly important desert forage plants in the Southwest.
Size: Medium to large sized, very robust bee, 1/2 to 1 inch in length.
HABITS
Distribution
Centris species are restricted to the Americas, and are found primarily in the tropics and deserts. Most North American species are found in the deserts of the southwest United States.
Number of species in North America
Eighty-five
Emergence Time
Spring to summer
Nesting Habit
Centris species are solitary, mostly ground-nesting bees, usually excavating their nests in loose, sandy soil; some species will use pre-existing tunnels.
Many species of Centris are known to collect plant oils, which they use to construct and waterproof the brood cells. Some species may also use the oils in place of nectar in provisioning their nests.
Additional Flowers Visited in Natural Areas
Parkinsonia (paloverde, Jerusalem thorn)
Prosopis (mesquite)
Psorothamnus (dalea, smoketree)
